Doing that enables strict mode in that function only.… Strict mode isn’t enabled here:
Only… Once we enter strict mode, there’s no going back.… next chapters, as we learn language features, we’ll see the differences between the strict and old modes… All examples in this tutorial assume strict mode unless (very rarely) specified otherwise.
The multiline mode is enabled by the flag m.
It only affects the behavior of ^ and $.… In the multiline mode they match not only at the beginning and the end of the string, but also at start… That’s because by default a caret ^ only matches at the beginning of the text, and in the multiline mode… “Start of a line” formally means “immediately after a line break”: the test ^ in multiline mode… “End of a line” formally means “immediately before a line break”: the test $ in multiline mode
A click on an element with the attribute data-toggle-id will show/hide the element with the given id:… Now, to add toggling functionality to an element – there’s no need to know JavaScript, just use the attribute… data-toggle-id.
Overlap outer variables.When in the light, can’t see anything in the darkness.… When in the darkness, can see everything in the light.
That’s where a lazy mode can help.… Lazy mode.The lazy mode of quantifiers is an opposite to the greedy mode.… Because we have a lazy mode for +?… The lazy mode doesn’t repeat anything without a need. The pattern finished, so we’re done.… As we’ve seen, the lazy mode is not a “panacea” from the greedy search.
The elem.classList is a special object with methods to add/remove/toggle a single class.… string value, good to manage the whole set of classes.
classList – the object with methods add/remove/toggle
There’s a checkbox at the bottom:
Now Cmd+Opt+C can toggle the console.
flag the search looks for all matches, without it – only the first match is returned.
m
Multiline mode… (covered in the chapter Multiline mode of anchors ^ $, flag "m").
s
Enables “dotall” mode,… More about that in the chapter Unicode: flag "u" and class \p{...}.
y
“Sticky” mode: searching… It has 3 working modes:
If the regular expression has flag g, it returns an array of all matches:
all the content is under “#shadow-root”:
First, the call to elem.attachShadow({mode… The mode option sets the encapsulation level.… shadowRoot = elem.attachShadow({mode: open|closed}) – creates shadow DOM for elem.… If mode="open", then it’s accessible as elem.shadowRoot property.
The tag name is always uppercase except in XML mode
The browser has two modes of processing… Usually the HTML-mode is used for webpages.… In HTML mode tagName/nodeName is always uppercased: it’s BODY either for <body> or <BoDy>… In XML mode the case is kept “as is”. Nowadays XML mode is rarely used.… Read-only.
nodeName/tagName
For elements, tag name (uppercased unless XML-mode).
Constructor mode test: new.target.… That can be used inside the function to know whether it was called with new, “in constructor mode… ”, or without it, “in regular mode”.
Shadow tree details are only provided for {mode:'open'} trees
If the shadow tree was created… with {mode: 'closed'}, then the composed path starts from the host: user-card and upwards.
mode.The mode option is a safe-guard that prevents occasional cross-origin requests:
"cors"… uses standard HTTP-cache rules and headers,
"no-store" – totally ignore HTTP-cache, this mode… Only works when mode is "same-origin".
Some modern features of the language (like classes that we’ll study in the future) enable strict mode… More in: The modern mode, "use strict".
Errors appear only in strict mode
In non-strict mode, no errors occur when writing to non-writable
In this case this is undefined in strict mode… In non-strict mode the value of this in such case will be the global object (window in a browser, we’
The browser tab is in the background mode.
The laptop is on battery saving mode.
All code inside the class construct is automatically in strict mode.
It has 3 modes:
If the regexp doesn’t have flag g, then it returns the first match as an array with
In strict mode, when a Function Declaration is within a code block, it’s visible everywhere inside that
That’s done with the “easeOut” transform.
easeOut.In the “easeOut” mode the timing function is put into
This is a bad practice and would cause an error in strict mode:
But, if the shadow tree has {mode: 'open'}, then we can figure out which elements assigned to a slot
The basics.XMLHttpRequest has two modes of operation: synchronous and asynchronous.
Should we turn on the lazy mode?
Unfortunately, that won’t help: if we replace \w+ with \w+?
Always “use strict”.Modules always work in strict mode.
If a variable is not found anywhere, that’s an error in strict mode (without use strict, an assignment
Lax mode, just like strict, forbids the browser to send cookies when coming from outside the site, but
Moreover, we do not need full-size photos in preview mode.